Changes in herbicide concentrations in Midwestern streams in relation to changes in use, 1989–1998

Scribner, Elisabeth A.; Battaglin, William A.; Goolsby, Donald A.; Thurman, E. Michael

doi:10.1016/s0048-9697(99)00547-1

Cited by 67 publications

(56 citation statements)

References 11 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In the eastern portion of the study area (sites [7][8][9][10][11][12][13][14][15][16][17][18][19][20], all the watersheds have a high percentage of their soils within HSGC and D, but significant differences were observed in areal herbicide loss rates. For example, sites 8, 11, and 13 had the highest areal loss rates, yet other watersheds with a similar or even higher proportion of runoff prone soils, such as sites 17-20, had considerably lower loss rates.…”

Section: Resultsmentioning

confidence: 99%

Watershed Vulnerability To Herbicide Transport in Northern Missouri and Southern Iowa Streams

Lerch

Blanchard

2003

Environ. Sci. Technol.

121

View full text Add to dashboard Cite

Herbicide contamination of streams has been well documented, but little is currently known about the specific factors affecting watershed vulnerability to herbicide transport. The primary objectives of this study were (1) to document herbicide occurrence and transport from watersheds in the northern Missouri/ southern Iowa region; (2) to quantify watershed vulnerability to herbicide transport and relate vulnerability to soil properties; and (3) to compute the contribution of this region to the herbicide load of the Missouri and Mississippi Rivers. Grab samples were collected under baseflow and runoff conditions at 21 hydrologic monitoring stations between April 15 and July 15 from 1996 to 1999. Samples were analyzed for commonly used soil-applied herbicides (atrazine, cyanazine, acetochlor, alachlor, metolachlor, and metribuzin) and four triazine metabolites (deisopropylatrazine, deethylatrazine, hydroxyatrazine, and cyanazine amide). Estimates of herbicide load and relative losses were computed for each watershed. Median parent herbicide losses, as a percentage of applied, ranged from 0.33 to 3.9%; loss rates that were considerably higher than other areas of the United States. Watershed vulnerability to herbicide transport, measured as herbicide load per treated area, showed that the runoff potential of soils was a critical factor affecting herbicide transport. Herbicide transport from these watersheds contributed a disproportionately high amount of the herbicide load to both the Missouri and Mississippi Rivers. Based on these results, this region of the Corn Belt is highly vulnerable to transport of herbicides from fields to streams, and it should be targeted for implementation of management practices designed to reduce herbicide losses in surface runoff.

show abstract

Section: Resultsmentioning

confidence: 99%

Watershed Vulnerability To Herbicide Transport in Northern Missouri and Southern Iowa Streams

Lerch

Blanchard

2003

Environ. Sci. Technol.

121

View full text Add to dashboard Cite

show abstract

“…Due to its extensive usage and moderate persistence, both alachlor and its metabolites could be accumulating in agriculturally related waters and the peak concentrations for alachlor of 25 lg L À1 in Kansas River and 4.8 lg L À1 in US groundwater were reported (Potter and Carpenter, 1995;Galassi et al, 1996;Thurman et al, 1996;Scribner et al, 2000;Squillace et al, 2002;Rebich et al, 2004). Concerns have been rising regarding the health risks associated with its occurrence in natural waters because alachlor is toxic and mutagenic (Tessier and Clark, 1995).…”

Section: Introductionmentioning

confidence: 99%

Degradation mechanism of alachlor during direct ozonation and O3/H2O2 advanced oxidation process

et al. 2010

View full text Add to dashboard Cite

a b s t r a c tThe degradation of alachlor by direct ozonation and advanced oxidation process O 3 /H 2 O 2 was investigated in this study with focus on identification of degradation byproducts. The second-order reaction rate constant between ozone and alachlor was determined to be 2.5 ± 0.1 M À1 s À1 at pH 7.0 and 20°C. Twelve and eight high-molecular-weight byproducts (with the benzene ring intact) from alachlor degradation were identified during direct ozonation and O 3 /H 2 O 2 , respectively. The common degradation byproducts included N-(2,6-diethylphenyl)-methyleneamine, 8-ethyl-3,4-dihydro-quinoline, 8-ethyl-quinoline, 1-chloroacetyl-2-hydro-3-ketone-7-acetyl-indole, 2-chloro-2 0 ,6 0 -diacetyl-N-(methoxymethyl)acetanilide, 2-chloro-2 0 -acetyl-6 0 -ethyl-N-(methoxymethyl)-acetanilide, and two hydroxylated alachlor isomers. In direct ozonation, four more byproducts were also identified including 1-chloroacetyl-2,3-dihydro-7-ethyl-indole, 2-chloro-2 0 ,6 0 -ethyl-acetanilide, 2-chloro-2 0 ,6 0 -acetyl-acetanilide and 2-chloro-2 0 -ethyl-6 0 -acetyl-N-(methoxymethyl)-acetanilide. Degradation of alachlor by O 3 and O 3 /H 2 O 2 also led to the formation of low-molecular-weight byproducts including formic, acetic, propionic, monochloroacetic and oxalic acids as well as chloride ion (only detected in O 3 /H 2 O 2 ). Nitrite and nitrate formation was negligible. Alachlor degradation occurred via oxidation of the arylethyl group, N-dealkylation, cyclization and cleavage of benzene ring. After O 3 or O 3 /H 2 O 2 treatment, the toxicity of alachlor solution examined by the Daphnia magna bioassay was slightly reduced.

show abstract

“…Conversely, other studies that examined long term trends between pesticide usage and pesticide concentrations observed decreases in concentrations of pesticides that are discontinued from use (i.e., alachlor) and increases in concentrations of pesticides that are newly introduced to the market (i.e., acetochlor) (Scribner et al, 2000;Vecchia et al, 2009). In these studies pesticide usage trends were reported as amount of pesticides applied rather than as the percentages of the watershed area receiving pesticide application.…”

Section: Discussionmentioning

confidence: 97%

“…In these studies pesticide usage trends were reported as amount of pesticides applied rather than as the percentages of the watershed area receiving pesticide application. It is assumed that changes in pesticide usage occurred over large spatial areas and encompassed the majority of the watershed area, but these previous studies (Scribner et al, 2000;Vecchia et al, 2009) did not provide this information. The conclusions that can be derived from these large scale studies (Scribner et al, 2000;Vecchia et al, 2009) are limited, but these studies do suggest that implementation of pesticide reduction practices in the majority of a watershed is needed to decrease in pesticide concentrations within the streams at the watershed scale.…”

Section: Discussionmentioning

confidence: 99%

Influence of Watershed Scale Atrazine Reduction Practices on Pesticides and Fishes within Channelized Agricultural Headwater Streams

Smiley¹,

King²,

Gillespie

et al. 2017

JSWSM

View full text Add to dashboard Cite

Application of pesticides within the watersheds of agricultural streams typically leads to increased instream pesticide concentrations that reduces water quality and threatens aquatic life. Pesticide reduction practices that reduce pesticide application within agricultural watersheds should reduce concentrations of pesticides within agricultural streams. Unfortunately, the influence of pesticide reduction practices on pesticides and the biota within agricultural headwater streams has not been empirically evaluated. We evaluated the watershed scale influence of atrazine reduction practices on pesticides, pesticide mixtures, and fish communities within channelized agricultural headwater streams in central Ohio. Water samples for pesticide measurements and fishes were collected in the spring and summer from a treatment stream (watershed size – 3.89 km2) that received atrazine reduction practices within 26 to 31% of its watershed during the first two years and then the watershed usage of these practices was reduced to less than 6% in the last four years. We also collected water samples and fishes during the same time from a control stream (watershed size 4.54 km2) that received atrazine reduction practices in 6% or less of its watershed during the study. Only three of 15 pesticide response variables and two of 15 fish community response variables indicated a potential effect of atrazine reduction practices. Mean differences in atrazine desethyl concentration, atrazine desethyl percent occurrence, and the number of pesticides between the control and treatment streams were greater during the time period with atrazine reduction practices than the time period without atrazine reduction practices. Mean differences in trophic guild richness and fish species composition similarity between the control and treatment streams occurred between time periods with and without atrazine reduction practices only during the summer. Our results suggest that implementing atrazine reduction practices to reduce atrazine usage within small portions (30% or less) of the watersheds of channelized agricultural headwater streams may not influence pesticides, pesticide mixtures, and fish community structure during the spring and summer.

show abstract

Changes in herbicide concentrations in Midwestern streams in relation to changes in use, 1989–1998

Cited by 67 publications

References 11 publications

Watershed Vulnerability To Herbicide Transport in Northern Missouri and Southern Iowa Streams

Watershed Vulnerability To Herbicide Transport in Northern Missouri and Southern Iowa Streams

Degradation mechanism of alachlor during direct ozonation and O3/H2O2 advanced oxidation process

Influence of Watershed Scale Atrazine Reduction Practices on Pesticides and Fishes within Channelized Agricultural Headwater Streams

Contact Info

Product

Resources

About